Granulated sugars have an excellent shelf life and can be stored in a cool, dry place in their original package for many years. When exposed to moisture, white granulated sugar tends to harden as it dries. Stirring or sifting will usually help to restore its granular state.
To soften brown sugar, place a piece of bread or apple in the jar for a few hours and the sugar will regain its original consistency. Hardened brown sugar can also be placed in the microwave for 20 seconds just before using it in a recipe.
Once opened, all liquid sugars like maple, corn and table syrups, honey, jams and jellies, must be refrigerated in airtight jars. If syrups begin to crystallize, place container in hot water to heat and then stir vigorously to restore liquid consistency.